Hydraulic resistor

ABSTRACT

A primary embodiment of the invention has a housing forming an interior chamber with an inlet and outlet formed therein; a rotatable resistor body situated within the chamber and rotatably driven by a shaft journaled in the housing has conduit means formed therein for completing communication between the interior chamber and outlet; a resiliently biased spoollike valve carried by the resistor body is centrifugally positioned so as to at a predetermined rotational speed of the resistor body terminate communication between the interior chamber and the outlet.

United States Patent 2,858,839 11/1958 Jackson 137/56 2,402,972 7/1946 Mitchell. 137/56 2,840,094 6/1958 Taplin 137/56 X 3,023,761 3/1962 Greenlees 137/56 3,026,890 3/1962 Begian 137/56 3,194,252 7/1965 Locher... 137/56 3,204,651 9/1965 Nicoletti 137/54 3,288,161 1 H1966 Frankowski 137/56 Primary Examiner-Clarence R. Gordon Attorney-Walter Potoroka, Sr.

ABSTRACT: A primary embodiment of the invention has a housing forming an interior chamber with an inlet and outlet formed therein; a rotatable resistor body situated within the chamber and rotatably driven by a shaft joumaled in the housing has conduit means formed therein for completing communication between the interior chamber and outlet; a resiliently biased spoollike valve carried by the resistor body is centrifugally positioned so as to at a predetermined rotational speed of the resistor body terminate communication between the interior chamber and the outlet.

HYDRAULIC RESISTOR BACKGROUND OF THE INVENTION Various forms of turbine engine fuel control assemblies i have been proposed for use in combination with gas turbine engines which may be classified broadly into three groups such as (l) turbojet, (2) turboprop and (3) turboshaft. The turbojet engine is one which relies upon jet thrust to develop its propulsive force, whereas, a turboprop has its turbine shaft coupled to a propeller, as well as to the compressor, so as to develop its propulsive force by slightly increasing the velocity of a large mass of air. The turboshaft engine differs from the turboprop in that the turbine shaft is coupled to an output shaft which drives something other than a conventional propeller. This output shaft may, for example, be a drive shaft for a land-based vehicle such as a truck, or a stationary powerplant.

Such proposed fuel control assemblies have employed particular pressure-responsive means sensitive to the engine burner inlet pressure, as a selected control parameter, for determining the desired rate of metered fuel flow to the engine burner section. However, when such fuel control assemblies are employed in combination with either turboprop or turboshaft engines problems may arise if certain precautions are not taken. That is, since the various control parameters as well as the above-selected control parameter are related and responsive to the gas producer section of the engine it can be seen that should the load on either the propeller or output shaft be suddenly removed, the power turbine of the engine could overspeed to some critical condition. Accordingly, in order to prevent the occurrence of such an overspeed condition, the pressure-responsive means sensitive to the engine burner inlet pressure, is caused to experience what may be considered as a signal conveying false information so as to result in the immediate reduction in the rate of metered fuel flow whenever it is sensed that the power turbine is approaching an undesirable overspeed condition.

SUMMARY OF THE INVENTION According to the invention, a centrifugally actuated hydraulic resistor assembly comprises a housing, a chamber formed in said housing, an inlet conduit formed in said housing communicating with said chamber, an outlet conduit formed in said housing, a resistor body including radially extending first and second arm portions situated within said chamber, a shaft carried by said body and journaled in said housing for rotation relative thereto, first conduit means formed in said resistor body communicating with said chamber, a valve member slidably received by said first conduit means and variably positioned with respect thereto in response to variations in cen trifugal force generated by the rotation of said shaft, said valve member comprising first and second axially spaced portions joined by an intermediate connecting portion of reduced cross-sectional area, said first axially spaced valve portion being continually received by said first conduit means and within said first arm portion in a manner so as to be eccentrically disposed with respect to the center of rotation of said shaft, second conduit means formed in said resistor body in general alignment with said shaft communicating between said first conduit means and said outlet conduit, resilient means carried within said second arm portion, and an adjustable anchor member carried within said second arm portion, said resilient means being operatively connected at one end to said second axially spaced valve portion and operatively connected at anend opposite to said one end to said adjustable anchor member, said first axially spaced valve portion being effective upon generation of a predetermined value of centrifugal force by rotation of said shaft to cause said second axially spaced valve portion to move against the resistance of said resilient means to a position terminating communication between said chamber and said second conduit means by preventing flow from said chamber through said first conduit means.

Accordingly, a general object of the invention is to provide a centrifugally actuated hydraulic resistor assembly which can be operatively connected to the engine turbine so as to be responsive to the speed thereof and thereby be effective to vary the effect of the pressure signal applied to the pressureresponsive means of the turbine engine fuel control.

Another object of the invention is to provide in a centrifugally actuated hydraulic resistor assembly centrifugally positioned valving means which is hydraulically balanced during its various stages of operation.

A further object of this invention is to provide in a centrifugally actuated hydraulic resistor assembly means for enabling related accessories to be rotatably driven in accordance with the speed of rotation experience by the hydraulic resistor assembly.

Other more specific objects and advantages of the invention will becomes apparent when reference is made to the following detailed description considered in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. ll diagrammatically illustrates a turbine engine in combination with a schematically illustrated fuel control (a portion of which is broken away and enlarged in cross section) and a speed-sensitive centrifugally actuated hydraulic resistor assembly (diagrammatically illustrated) ofthe invention;

FIG. 2 is a top plan view ofa centrifugally actuated hydraulic resistor assembly constructed in accordance with the in vention;

FIG. 3 is a cross-sectional view of the hydraulic resistor assembly of FIG. 2 with the housing thereof being sectioned generally on the plane of line 33 of FIG. 2 and the internal portion thereof being sectioned generally on the plane of line 4-4 of FIG. 2 and looking in the direction of the arrows;

FIG. 4 is an axially extending cross-sectional view of another embodiment of the invention taken generally on the plane ofline 6--6 of FIG. 5 and looking in the direction ofthe arrows; and

FIG. 5 is an end elevational view taken generally on the plane ofline 5-5 of FIG. 4.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now in greater detail to the: drawings, FIG. I illustrates, by way of example, a split shaft turbine engine It] as being comprised of a suitable housing 12 containing therein a radial compressor 14 operatively connected as by a shaft 16 to a first-stage rotor or compressor turbine 18. A power turbine 20 situated generally coaxially with said compressor turbine 13 and mounted on an engine output shaft 22, is adapted to drive some load through any cooperating power transmission means. Gears 24 and 26, of which gear 24 is operatively connected to shaft 22 for rotation therewith, cooperate to drive, as by motion-transmitting means 28, a second speed sense 30.

FIG. I also illustrates, diagrammatically, a fuel control assembly 32 with a fragmentary portion thereof broken away and shown in enlarged cross section. Fuel supplied by a suitable source 34 passes into fuel control 32 and having been metered therein passes, as through conduit means 36, to the burner 38 of the engine 10.

As illustrated, the fuel control 32 may be comprised of a section 40 responsive to burner inlet pressure, P,;,, as a control parameter for the operation of the fuel control assembly 32. Section 40 may be comprised of a diaphragm assembly 42 peripherally secured between a housing portion 44 and a cooperating cover member 46 so as to form two generally distinct but variable chambers 48 and 50. Diaphragm 42 is operatively connected to a motion-transmitting rod 52 slidably received in housing portion 44- and rod 52 is operatively connected to one end of a lever 54 which, in turn, is

secured to a transverse pivot shaft 56 extending through a wall of a chamber 58. A second lever 60, also secured to shaft 56,

is generally contained within chamber 58 in a manner so as to operatively connect as by suitable motion and/or force-transmitting means 62 to related control components within the fuel control assembly 32.

Burner inlet pressure, P sensed as by a probe 64 is directed to chamber 48 as by conduit means 66 and 68 and a restriction 70 in series therewith. Chamber 48, containing a compression spring 72, normally urging diaphragm assembly 42 to the right, communicates with the ambient atmosphere by means of a conduit 74 which also contains a restriction 76. Because of the flow afforded t4, the combination of restrictions 70 and 76 the pressure, P within chamber 48, although related to the value of P will be somewhat less than the value of P Chamber 50, containing a compression spring 78 normally urging diaphragm assembly 42 to the left, communicates with ambient atmosphere as by means of a conduit 80 which communicates with conduit 74 downstream of restriction 76. Threadably adjustable stop members 82 and 84 are provided in order to limit the movement of the diaphragm assembly to respectively the left and right.

As also diagrammatically illustrated in FIG. 1, the fuel control assembly 32 may be provided with a speed sense device 86 operatively connected toshaft 16 as by means of gears 88 and 90 and suitabletransmission-means 92. The purpose of a;

speed sense such as 86 is to.continually provide a pressure signal indicative of the speed of the gas producer section (compressor 14 and compressor drive turbine 18). Such speed signals generated by the device 86 are employed as an input signal to the fuel control as one of the control parameters on which the weight rate of metered fuel depends. Such a device 86 may be functionally equivalent to the speed sense as shown, for example, at 140 in US. Pat. No. 3,073,115 is sued Jan. 15, 1963, to Warren H. Cowles, et al.

However, as previously stated, the invention is primarily concerned with a speed sense structure 30 which serves to ultimately prevent not only additional fuel flow but also to reduce the rate of fuel flow to the engine whenever engine overspeed conditions are sensed. This could occur, for example, if at some engine operating condition, the load imposed on output shaft 22 were suddenly removed. This might result in a dangerous overspeed condition and the only way to correct this is to at such time reduce the rate of fuel flow to the gas producer section and in effect override the various parameters which have determined the initial rate of fuel flow to the engine. This is accomplished in the following manner.

For example, if it is assumed that rightward movement of rod 52 in section 40 creates an ultimate signal of a demand for increased fuel flow, then it can be seen that if diaphragm 42 is somehow caused to move to the left, carrying rod 52 with it, that the signal received by the fuel control assembly 32 will be one indicating a demand for a reduction in fuel flow. As will be seen, conduit 74 communicates, via conduit means 94, with speed sense 30 and during periods of engine operation wherein the speed of power turbine 20 is below a predetermined critical speed, such communication is completed through the speed sense 30 to the ambient atmosphere. However, when an overspeed is sensed, the communication through speed sense 30 is at least sufficiently restricted as to cause the pressure within chamber 50 to approach the pressure within chamber 48. This, of course, permits spring 78 to move diaphragm 42, and rod 52 operatively connected thereto, to the left reducing fuel flow to the burner 38. 1f the communication through speed sense 30 should be totally terminated, for any period of time, the pressure within both chambers 48 and 50 would, of course, be equal to P FIGS. 2 and 3 illustrate one preferred embodiment of a speed sense constructed in accordance with the inventionas being comprised of a housing 96 cooperating with a cover plate 98 and seal 100 to define a chamber 102 which is adapted toreceive therein a hydraulic'or pneumaticresistor assembly 104. Theresisto'r assembly 104 is illustrated as being comprised of a piloted shaft portion 106 formed integrally with and normal to a main body 108 having radially extending portion 110 in a manner soas to open, at its opposite ends, to

the chamber 102 and a second conduitor passageway formed in body 108. An additional conduit 10?, formed in arm bodyportion 110,-intersects conduit 118 and serves to communicate between chamber 102 and conduit 118. As can be seen, the point at which passageway or chamber 120 and conduit 118 meet each other. provides a shoulderlike portion 122 which, at times, cooperates with a valving portion 124 of valve member 116 in order to prevent communication between conduitl 18 and 120.

A threaded portion formed in arm body portion 112 threadably engages a. tubular .or cup-shaped adjustment member 126 which may have its radially outer end open to communication with chamber 102 while its radially inner end has an aperture formed therethrou'gh for the reception therein of the other end portion. l28 o f valve member 116. Suitable O- ring-type seals130, and are provided inorder to minimize if not totallyprevent any pressure leakage between related compone nt s i Atens ion spring H justment member 126 has 0 M y th slot formed in end 128ofval v j I iid secured therein as byananchor pin.l3 6 retained by end 128 of valve 116 transversely thereof. The other end of spring 134 is ure t h lly out?! sndpf-sdj stmsm member 126 by virtue of. asecond .anc hor,.pin l 38, its opposite ends secured vwithinsuitable aligned radially directed apertures and 142. lf desired, the radially outer end of adjustment member 126 may be castled ,or otherwise provided with a tool-engaging surface in order: to. permit the insertion of a tool through the access aperture 146 (normally closed by a removable plug 144) so as to, at assembly, adjust the relative initial at rest position of valve member 116. Such adjustment may of course be effected by engaging anchor pin 138 and thereby causing threadable rotation of cup-shaped adjustment member 126 connected thereto.

The end of motion-transmitting means 28 may take the form, cross-sectionally, of a square, or some other suitable keying configuration, and be received within an aperture or recess 148, formed in pilot shaft 106, of a complementary cross-sectional configuration thereby establishing a driving relationship therebetween. Shaft 106 may be journaled within a flanged bearing 150 for rotation therein while the opposite side of body 108 may be placed in engagement with an annular thrust bearing 152, carrying a seal 154, situated within a bore formed internally of housing 96. Suitable shims, or an annular spring, may be provided at the opposite end of thrust bearing 152, as indicated generallyat 156, in order to achieve the desired assembly force against body 108.

A conduit portion 158 formed through a wall of body 108, so asto be generally aligned with pilot shaft 106, serves to communicate between passageway 'or chamber 120 and conduit 160 through the annular thrust bearing 152. Conduit 160, formed in housing 96, communicates with the ambient atmosphere while an inlet conduit 162 (FIG. 2) serves to communicate between chamber 102 and conduit means 94 leading to the sourceoffiuid pressure, as also shown at 74 of FIG. 1.

Cover plate 98 may be secured to housing 96 as by screws 164 (FlC Z) while thea ssembly may be secured to a suitable portion of related housing 44 as by additional screws one of which is shown at 166.

As is evident, as power turbine 20rota tes output shaft 22, transmission means .28 ,causes,.tlie resistor ,assembly 104 to rotate about its shaft l,06 in,,ac,cgrdance therewith. At the same pressure P is communicated to chamber 48 from where the superatmospheric pressure is communicated via conduit 74, conduit means 94, inlet conduit 162 to chamber 102 of speed sense 30. The pressure thusly communicated to chamber 102 is further directed through conduit 109, conduit 118, chamber 120, conduit 158 and through conduit 160 to ambient atmosphere.

As the speed of rotation of resistor assembly 104 increase, the centrifugal force of valve member 116 increases tending to move valve 116 radially outwardly with respect to valve body 108 in a manner causing valving portion 124 to more closely approach valving shoulder or seat 122. The calibration and rating of spring 134 as well as the initial at rest position of valve member 1l6 as determined by the adjustable member 126 are so selected as to cause valving portion 124 to seat against valve seat 122 when the speed of rotation of resistor assembly 104 has attained a preselected speed reflective of a predetermined critical rotational speed of output or power turbine 20.

When this happens further communication of the superatmosphen'c pressure to ambient atmosphere through conduit 118 is precluded by virtue of valving portion 124 being closed against seat 122. Accordingly, the pressure within chambers 48 and 50 (FIG. 1) becomes equal thereby enabling spring 78 to move diaphragm assembly 42 and rod 52 to the left as previously described.

As generally depicted in FIG. 2, it can be seen that the admission of fluid pressure to the chamber 102 is generally tangential to and in the direction of rotation of resistor assembly 104. This serves to lessen the occurrence of any undue pressure disturbances caused by the rotational action. Further, it can be seen that when the valve member 116 is in a position as, for example, illustrated in FIG. 3, the radially outermost surface of valve end portion 114 is exposed to the pressure within chamber 102 and that the opposite end surface of valve end portion 128 is also exposed to the same pressure. Consequently, as regards ends 114 and 128 they are continually hydraulically balanced, (the effective cross-sectional areas of valve portions 114 and 128 being substantially equal). Also, during this time, the radial surfaces formed as a consequence of the necked-down intermediate portion 168 of valve 116 are exposed to substantially the same pressure. Therefore, they too are hydraulically balanced. This hydraulically balanced condition continues to exist even through valving portion 124 terminates flow through conduit 118. The only difference is that at such time the pressure, applied to the surfaces considered, will be significantly greater. Another feature of the invention is that conduit 109 is situated so as to communicate with the chamber 102 by having openings terminating in the axially spaced end surfaces of resistor body 108. This in turn serves to further minimize the possibility of conveying any pressure fluctuations possibly caused by rotational action of resistor assembly 104.

FIGS. 4 and 5 illustrate a second embodiment of the invention wherein means are provided for enabling the speed sense 200 to provide a drive connection for a related accessory.

Referring in greater detail to FIG. 4, it can be seen that the speed sense assembly 200 is illustrated as being comprised of a housing 202 cooperating with a cover plate 204 and seal 206 to define a chamber 208 which is adapted to receive therein a hydraulic or pneumatic resistor assembly 210. The resistor assembly 210 is shown as being comprised of a piloted shaft portion 212 formed integrally with and normal to a main body 214 having radially extending armlike portions 216 and 218 which are in general alignment with each other. One end 220 of a valve member 222 is slidably received within a valve guiding conduit 224 formed through body arm portion 218 in a manner so as to open at its opposite ends to chamber 208 and a second conduit or passageway 226 formed principally in body arm portion 216. An additional conduit portion or aperture 228, formed through a wall of resistor body 214, closely receives therein one end of a generally tubular shaft member 230 which may be secured to resistor body 214, for rotation therewith, as by a pin 232 situated generally transversely of shaft 230. The other end 234 of shaft 230 may be joumaled within a bearing 236 situated within a bore 238 of housing 202. Bore 238, formed within extension 240 of housing 202, has an enlarged portion which contains a flanged bushinglilte thrust member 242 and an O-ringlilte seal 244 situated thereabout. The enlarged portion of bore 238 forms a step or shoulder portion 246 which serves as a seat for one end of a compression spring 248 which continually urges thrust member 242 into engagement with resistor body 214. A flanged bearing 250 serves to journal shaft portion 212 within a cooperating bore 252 formed in cover 204.

Chamber or passageway 226 includes an internally threaded portion for threadably engaging a tubular adjustment member 254 having an anchor pin.256 secured thereto for anchoring one end of a tension spring 258. The other end of spring 258 may be similarly secured to end portion 260 of valve member 222 as by a second transversely carried anchor pin 262. End portions 220 and 260 of valve member 222 are preferably of like cross-sectional diameter as to permit end portion 260 to be slidably received within guide conduit 224 upon sufficient rotational speed of the resistor assembly 210. The adjustment member 254 preferably includes a plug of material 264 somewhat deformable so as to present some interference with the internal threads in order to thereby maintain the adjustment member 254 in a selected position. An access aperture 266 and plug 268, like that of FIG. 3, are also preferably provided.

Shaft 212 has a recess 270 formed therein for drivingly engaging the end of motion transmission means 28 while end 234 of hollow shaft 230 is similarly provided with an internal surface 272 for drivingly engaging a suitable connection 274 of a related structure 276 to be driven in relation to the speed of rotation of transmission means 28.

The entire speed sense may of course be detachably secured as by screws, one of which is shown at 1278, to a related support such as a portion of housing 44.

An inlet conduit 280 formed in housing 202 serves to communicate between chamber 208 and conduit means 94 (FIG. 1) in the same manner as inlet conduit 162 of FIG. 2.

During operation at speeds below the predetermined critical speed, motion transmission means 28 rotates the resistor assembly 210; however, communication exists from conduit means 94, inlet conduit 280, chamber 208, through adjustment member 254, passageway 226, through the hollow or tubular shaft 230, through apertures 282 formed in shaft 230, radially thereof, and through conduit 284 in housing extension 240 to the ambient atmosphere.

However, as previously described with reference to FIGS. 2 and 3, when the predetermined critical speed is attained valve end portion 260 may be moved to a point where it is slidably received within conduit 224 thereby terminating further communication between chamber or passageway 226 and conduit 224 and the interior of tubular shaft 230. Consequently, the pressure within chambers 40 and 50 (F1G. 1) again becomes substantially equal causing spring 78 to move diaphragm as sembly 42 and rod 52 to the left.

In view of the description relative to FIG. 3, it should be apparent that valve member 222 is also hydraulically balanced, whether it be open orclosed, just as the valve member 116 of FIG. 3.

The invention has been disclosed in an environment where the fluid pressure is transmitted in a pneumatic medium. However, it is obvious that the precise medium employed for transmitting such pressures is not important and that the invention may be employed in the manner described whether the medium be liquid or pneumatic. Accordingly, the term, hydraulic, as employed herein as well as the claims contained herein is intended to embrace in a generic sense any such fluid pressure medium.

Although only two selected embodiments of the invention have been disclosed and described it is apparent that other embodiments and modifications of the invention are possible within the scope of the appended claims.

What I claim as my invention is:

l. A centrifugally actuated hydraulic resistor assembly, comprising a housing, a fluid chamber formed in said housing, an inlet conduit formed in said housing communicating tangentially with said chamber, an outlet conduit formed in said housing, a resistor body including radially extending first and second arm portions situated within said chamber, a shaft carried by said body and journaled in said housing for rotation relative thereto in flow direction, first conduit means formed in said resistor body communicating with said chamber, a valve member slidably received by said first conduit means and variably positioned with respect thereto in response to variations in centrifugal force generated by the rotation of said shaft, said valve member comprising first and second axially spaced portions joined by an intermediate connecting portion of reduced cross-sectional area, said first axially spaced valve portion being continually received by said first conduit means and within said first arm portion in a-manner so as to be eccentrically disposed with respect to the center of rotation of said shaft, second conduit means formed in said resistor body in general alignment with said shaft communicating between said first conduit means and said outlet conduit, resilient means carried within said second arm portion, and an adjustable anchor member carried within said second arm portion, said resilient means being operatively connected at one end to said second axially spaced valve portion and operatively connected at an end opposite to said one end to said adjustable anchor member, said first axially spaced valve portion being effective upon generation of a predetermined value of centrifugal force by rotation of said shaft to cause said second axially spaced valve portion to move against the resistance of said resilient means to a position terminating communication between said chamber and said second conduit means by preventing flow from said chamber through said first conduit means.

2. A centrifugally actuated hydraulic resistor assembly according to claim 1 including a thrust bearing carried by said housing and sealingly engaging said resistor body on a side thereof opposite to said shaft.

3. A centrifugally actuated hydraulic resistor assembly according to claim 1 including a second shaft having one end operatively connected to said resistor body in a manner whereby a passageway formed in said second shaft is placed in continuing communication with said second conduit means, and additional conduit means formed in said second shaft generally radially thereof for completing communication between said passageway and said outlet,

4. A centrifugally actuated hydraulic resistor assembly according to claim 1 including a second shaft having one end operatively connected to said resistor body in a manner whereby a passageway formed in said second shaft is placed in continual communication with said second conduit means, additional conduit means formed in said second shaft generally radially thereof for completing communication between said passageway and said outlet, and a coupling surface formed generally at the other end of said second shaft adapted for drivingly engaging suitable motion-transmitting means for driving an associated accessory.

5. A centrifugally actuated hydraulic resistor assembly according to claim 1 including a second shaft having one end operatively connected to said resistor body in a manner whereby a passageway formed in said second shaft is placed in continual communication with said second conduit means, additional conduit means formed in said second shaft generally radially thereof for completing communication between said passageway and said outlet, a coupling surface formed generally at the other end of said second shaft adapted for drivingly engaging suitable motion-transmitting means for driving an associated accessory, a thrust bearing carried by said housing and situated about said second shaft near said one end of said second shaft so as to sealingly engage said resistor body on a side thereof opposite to said first-mentioned shaft, resilient means engaging said thrust bearing and continually resiliently biasing said thrust bearing toward said resistor body, and journal bearing means carried by said housin and situated about said second shaft near the other end of sai second shaft.

6. A centrifugally actuated hydraulic resistor assembly according to claim 1 wherein said resilient means comprises a tension spring.

7. A centrifugally actuated hydraulic resistor assembly according to claim 1 wherein said anchor member comprises an externally threaded member threadably engaging an internally threaded portion of said second arm portion, said threaded member being effective upon threadable axial adjustment thereof relative to said second arm portion to vary the position of said valve member relative to said resistor body for any preselected rotational speed of said shaft and resistor body.

8. A centrifugally actuated hydraulic resistor assembly according to claim 1 wherein said anchor member comprises an externally threaded tubular member threadably engaging an internally threaded portion of said second arm portion. 

1. A centrifugally actuated hydraulic resistor assembly, comprising a housing, a fluid chamber formed in said housing, an inlet conduit formed in said housing communicating tangentially with said chamber, an outlet conduit formed in said housing, a resistor body including radially extending first and second arm portions situated within said chamber, a shaft carried by said body and journaled in said housing for rotation relative thereto in flow direction, first conduit means formed in said resistor body communicating with said chamber, a valve member slidably received by said first conduit means and variably positioned with respect thereto in response to variations in centrifugal force generated by the rotation of said shaft, said valve member comprising first and second axially spaced portions joined by an intermediate connecting portion of reduced cross-sectional area, said first axially spaced valve portion being continually received by said first conduit means and within said first arm portion in a manner so as to be eccentrically disposed with respect to the center of rotation of said shaft, second conduit means formed in said resistor body in general alignment with said shaft communicating between said first conduit means and said outlet conduit, resilient means carried within said second arm portion, and an adjustable anchor member carried within said second arm portion, said resilient means being operatively connected at one end to said second axially spaced valve portion and operatively connected at an end opposite to said one end to said adjustable anchor member, said first axially spaced valve portion being effective upon generation of a predetermined value of centrifugal force by rotation of said shaft to cause said second axially spaced valve portion to move against the resistance of said resilient means to a position terminating communication between said chamber and said second conduit means by preventing flow from said chamber through said first conduit means.
 2. A centrifugally actuated hyDraulic resistor assembly according to claim 1 including a thrust bearing carried by said housing and sealingly engaging said resistor body on a side thereof opposite to said shaft.
 3. A centrifugally actuated hydraulic resistor assembly according to claim 1 including a second shaft having one end operatively connected to said resistor body in a manner whereby a passageway formed in said second shaft is placed in continuing communication with said second conduit means, and additional conduit means formed in said second shaft generally radially thereof for completing communication between said passageway and said outlet.
 4. A centrifugally actuated hydraulic resistor assembly according to claim 1 including a second shaft having one end operatively connected to said resistor body in a manner whereby a passageway formed in said second shaft is placed in continual communication with said second conduit means, additional conduit means formed in said second shaft generally radially thereof for completing communication between said passageway and said outlet, and a coupling surface formed generally at the other end of said second shaft adapted for drivingly engaging suitable motion-transmitting means for driving an associated accessory.
 5. A centrifugally actuated hydraulic resistor assembly according to claim 1 including a second shaft having one end operatively connected to said resistor body in a manner whereby a passageway formed in said second shaft is placed in continual communication with said second conduit means, additional conduit means formed in said second shaft generally radially thereof for completing communication between said passageway and said outlet, a coupling surface formed generally at the other end of said second shaft adapted for drivingly engaging suitable motion-transmitting means for driving an associated accessory, a thrust bearing carried by said housing and situated about said second shaft near said one end of said second shaft so as to sealingly engage said resistor body on a side thereof opposite to said first-mentioned shaft, resilient means engaging said thrust bearing and continually resiliently biasing said thrust bearing toward said resistor body, and journal bearing means carried by said housing and situated about said second shaft near the other end of said second shaft.
 6. A centrifugally actuated hydraulic resistor assembly according to claim 1 wherein said resilient means comprises a tension spring.
 7. A centrifugally actuated hydraulic resistor assembly according to claim 1 wherein said anchor member comprises an externally threaded member threadably engaging an internally threaded portion of said second arm portion, said threaded member being effective upon threadable axial adjustment thereof relative to said second arm portion to vary the position of said valve member relative to said resistor body for any preselected rotational speed of said shaft and resistor body.
 8. A centrifugally actuated hydraulic resistor assembly according to claim 1 wherein said anchor member comprises an externally threaded tubular member threadably engaging an internally threaded portion of said second arm portion. 